1. Field of the Invention
The present invention refers to a cloverleaf microgyroscop and a method of manufacturing a cloverleaf microgyroscop that contains a single crystal silicon cloverleaf-shaped resonator and integrated post attached to the leaves.
2. Description of Related Art
U.S. Pat. No. 5,894,090 to Tang et al., which is incorporated herein as reference, discloses a micromachined symmetric leaf structure having a plurality of symmetrically disposed leaves about a defined center. At least one micromachined spring symmetrically is disposed with respect to the symmetric leaf structure and supporting the symmetrical leaf structure, a rim/base structure to which the spring is coupled. The rim/base structure includes a plurality of sensing and drive electrodes and a circuit electrically coupled to the electrodes included within the rim/base structure. The circuit provides drive signals to the drive electrodes to oscillate the symmetric leaf structure and to receive a sensing signal from the sensing electrodes to detect response of the oscillating symmetric leaf structure to physical phenomena exterior to the micromachined resonator. The micromachined resonator has a manually inserted post. It shows a lack of a silicon based vacuum encapsulation. A low yield is obtained during the separation. The manufacturing of the resonator involves high fabrication costs. It shows large vibration sensitivity and no clear path to electronic integration.
The known manufacture processes make it very difficult to manufacture a micro gyroscope. The central post is inserted by hand, the device has to be vacuum packaged in a custom package and there is no ability to integrate control electronics with the silicon structure.
What is needed is a cloverleaf microgyroscope and a process for manufacturing a cloverleaf microgyroscope with an integrated central post and electronics with the resonator and vacuum package at wafer-level with a single crystal silicon construction.